AFAIK that popup has always been there, i get it if i don't refresh the page prior to vault opening, and you also get it if it's already sold out. It won't actually say sold out until you refresh and the site returns a status change to indicate no buy button. your version is loaded thinking it can still be bought and will return an error. unfortunately the error is always a vague "cannot accept at this time" for any reason something can't be obtained, whether too early, sold out, and even vpn.
awa has been around for almost a decade, and it's amazing the site is still duct tape and chopsticks. i think it's run by wordpress so all kinds of funny glitches exist. look up the company that runs it, named in the TOS, it's a tiny number of staff.